Heating apparatus



Aug. 93 A. T. LEWIS 1,819,608

HEATING APPARATUS Filed Aug. 28, 1928 INVENTOR:

ATTORNEY.

reamed Aug. is, 1931 ALEXANDER THORNTON LEWIS, F MERION, PENNSYLVANIA, ASSIGNOR TO YORK HEATING AND VENTILATING CORPORATION, OF PHILADELPHIA, PENNSYLVANIA, A

CORPORATION OF PEN N SYLVAN IA HEATING- APPARATUS Application filed August 28, 1928.

only be had by varying the temperature of heat exchange unit or varying the volume of air passing over that unit in a given time, all of which introduce loss factors which contribute to ineificient operation. Some of the objects of the present invention are to provide an improved heating unit which is simple in construction and efficient in operation; to provide an indirect heating unit wherein temperature control can be had at will without loss in efficiency to provide a heating unit wherein the temperature of the heating medium can be maintained constant while the temperature and volume of the discharged air can he so varied to suit conditions; to provide aheating unit wherein the temperature of the heating medium and the velocity of the air passing through the unit can both be main-- tained constant while the heat units in the discharged air can be varied ,to suit conditions; and to provide other improvements as will hereinafter appear.

In the accompanying drawings:

Fig. 1 represents a perspective of a heating unit embodying one form of the present invention;'

Fig. 2 represents a perspective of the discharge side of the unit; and

Fig. 3 represents aperspective of one form of coil used with the unit of the present invention.

Referring to the drawings, one form. of the present invention consists generally of 0 a casing 10, a heat ,exchange unit 11, and a plurality of fans 12 and 13 arranged to blow Serial N 0. 302,455.

air through the casing 10 in contact with the unit 11. In accordance with the present invention, the construction of the heat exchange unit 11 is such that it is uniformly heated by the steam or other heating me dium employed for heating purposes, and one portion thereof, under operating conditions, always gives off a lower number of heat units than the remaining portion of the unit 11. A construction well suited for this dual temperature result is here shown by way of example in the form of aplurality of return bend pipes 14 having ends respectively terminating in two headers 15 and 16 provided respectively with coupling nipples 17 and 18 for connection to a steam supply and to an exhaust or drain line. As shown, the headers 15 and 16 are located in relatively close proximity but vertically staggered to allow for the drainage pitch of the circulating pipes 14. Also, each pipe 14 is provided with fins 20 though neither the fins nor the specific coil construction alone form the subject-matter of the present invention, and it is to be understood in the combination of this invention, many other coil constructions may be employed.

The casing 10 is arranged to enclose the coil unit 11 but is suitably apertured to allow the nipples" 17 and 18 to project at one end for connection with the associated supply and discharge pipes.

The fan side-of the casing 10 is provided With two inlet openings 21 and 22 respectively in the discharge paths of the fans 12 and 13, said inlet openings 21 and 22 and the fans 12 and 13 being so located and arranged that the blast of air from the fan 12 passes through a different portion of the coil unit 10 from that of the fan 13. The two columns of air blown from the fans 12 and 13 pass transversely through the coil unit substantially parallel to each other and leave the casing 10 through a common outlet 23, which ishere provided by forming the outlet side of the casing 10 as. a rectangular frame suitably bolted, riveted or otherwise secured to the associated top, bottom and ends of the casing 10. The fans 12 and 13 are preferably of the blade type driven by electric motors 24, which are attached to the side of the casing 10 by suitable straps supporting them respectively in axial register with the inlet openings 21 and 22. Thus when the fans are running, two columns of air will be blown through the inlets to traverse the coils of the unit 11 and leave by the common outlet 23 with the air in the desired, predetermined temperedcondition.

' Since the steam receiving end portion of the unit 10 gives off more heat units than the return bend portion of the unit 10, and since the fan 12 blows air through the unit coil portion of higher heat capacity while thefan 13 blows air through the unit coil portion of lower heat capacity, it follows that the highly desirable regulation of the amount of heat given to the discharged air to meet various conditions is possible by selective control of the fans. Thus the apparatus is capable of functioning to discharge heated air when both fans are at rest, when fan 12 is running and fan 13 is at rest, when fan'13 is running and fan 12 is at rest, and when both fans are running. Under the first condition, which depends upon a natural circulation of air through the coil unit 10, it has been found that approximately six percent of the available heat units are absorbed by the air as it passes on the surface of the coil structure; under the second condition, the blast of air from fan 12 will absorb sixty to seventy percent of'the available heat units; under the third condition, the blast of air from fan 13 Will absorb fifty to sixty percent of the available heat units; while. under the last condition, the blasts of air from the fans 12 and 13 will absorb substantially e hundred percent of the available heat units. This air control result is not brought about merely by adding a second fan to a heating unit, but by reason of a heat exchange unit having one portion of a lower heating capacity than the other and placing the portion of lower heating capacity under the control of one fan, while the other, or higher heating capacity portion, is under the control of a second fan separably operating and separably controlled. This construction gives a control ranging from'six percent to one hundred percent of available thermal units.

From the foregoing, it will be apparent that a complete unitary heat exchange unit has been devised whereby the velocity of the therefore be operated at maximum efliciency because the main control factors are con-.

stant.

Having thus described my invention, I claim:

1. A heat exchange unit comprising a cas ing having means for admitting air to one side thereof and means to discharge air at another part thereof, a heat exchange coil mounted in Saidpasing and constructed so that one portion thereof normally gives up a higher number of heat units than the reinlets in one side thereof and an air outlet.

at the opposite side thereof, one of said inlets being located to admit air against the return bend portion of said coil, and the other of said inlets being located to admit air against the heat receiving end only of said coil, and separately controlled. fans for respectively blowing air into said inlets through said coil in two separate paths and out of said discharge outlet.

3. A heat exchange unit comprising a pipe coil of return bend construction, a. casing enclosing said coil having two air inlets in one side thereof and an air outlet at the opposite side thereof, one of said inlets being located to admit air against the return bend portion of said coil and the other of said inlets being located to-admit air against the return ing portion of said coil, and separately controlled fans for respectively blowing air into said inlets through said coil in two separate paths and out of said discharge outlet.

41. A heat exchange unit comprising a casing provided with means for admitting air at one side thereof and discharging air at the other side thereof, circulating pipes for a heating medium interposed between said air admitting and air discharging means, and a plurality of separately controlled fans for causing air to travel about said pipes in one or more streams and to discharge from said casing whereby the heating eifect of the dis charged air is maintained economical under all operating conditions.

Signed at Philadelphia, county of Philadelphia, State of Pennsylvania, this 22nd day of August, 1928.

ALEXANDER THORNTON LEWIS. 

